Counterbalanced humidifier



Aug. 7, 1962 M. A. POWERS COUNTERBALANCED HUMIDIFIER 5 Sheets-Sheet l Filed Sept. 16, 1958 mhllh o@ f/Ww ATTORNEYS Aug. 7, 1962 M. A. POWERS 3,048,163

COUNTERBALANCED HUMIDIF'IER Filed sept. les,l 1958 5 Sheets-Sheet 2 Aug 7, 1962 M. A. POWERS 3,048,163

COUNTERBALANCED HUMIDIFIER Filed Sept. 16, 1958 5 Sheets-Sheet 3 INVENTOR Mm# @ff/fis www ATTORNEYS Aug. 7, 1962 M. A. POWERS COUNTERBALANCEDHUMIDIFIER 5 Sheets-Sheet 4 Filed sep't. 1s, 1958 R O5 my EW .Mp m

y/M// ATTORNEYS Aug. 7, 1962 M. A. POWERS 3,048,163

COUNTERBALANCED HUMIDIFIER Filed Sept. 16, 1958 5 Sheets-Sheet 5 TILT TYPE AND COUNTERBALANCED HUMIDIFIERS WATER PRESSUREDEPTH COMPARISON INV EN TOR ///zfo/v pan/Aas ATTORNEYS BY Myfw WATER PRESSURE- POUNDS PER SOJNCH dUnited States Fatent 3,04S,163 COUNTERBAIJANCED HUlt/IIDIFIER Milton A. Powers, Grosse Pointe, Mich., assigner to Skuttle Manufacturing Co., Mitford, Mich., a corporation of Michigan Filed Sept. 16, 19%, Ser. No. 761,314 16 Claims. (Cl. 126-113) This invention relates to humidiliers and more particularly to automatically relillable counterbalanced humidiiers adapted to be mounted in a wall aperture of a plenum chamber or duct of a hot air heating system and the like.

Many types of humidiflers have been proposed for use in hot air heating systems. Humidifiers in modern hot air heating systems are usually located in the plenum chamber of the hot -air furnace or in the main duct leading from the furnace. It is `desirable that these humidiiiers be automatically reillalble with water to a predetermined level from a constant water source, the water-flow being automatically controlled by water-level responsive valve means. Such automatically reiillable humidiliers are usually complicated to manufacture, install, and service. Also, the necessary adjustments thereon are usually diiicult to make and maintain satisfactorily.

With the foregoing considerations in view, a primary object of this invention is to provide an improved automatically reillable humidifier of the type having a receptacle such as a reservoir pan tiltable in response to the water level therein to control flow from a water source, the humidilier having embodied therein novel features for simplied and more economical manufacture, easier adjustment and maintenance, and trouble-free operation.

Another object is to provide a novel humidifier construction which may be installed in areas subject to wide iluctuations in water pressure and which will operate reliably within narrow limits of water level in the reservoir and without overow under extremely high water pressures so encountered.

Another object is to provide a novel humidifier construction with all operating parts located within the heated air zone of the furnace or duct yet which remain unaffected by said heat which heretofore has caused precipitation of lime within the valve member and water line connections resulting in failure in operation.

Another object is to provide a novel resilient valve seat member which is easily accessible for inspection, may be progressively positioned to present a multiplicity of new valve surfaces as wear occurs, and is provided with integral flanges which serve both to retain the member in a controlled position and also deflect water spray from the nozzle downward into the reservoir.

Other objects and advantages of the invention will become apparent from the following detailed description and drawings, in which:

FIGURE l is a longitudinal vertical sectional View of the humidifier of this invention mounted in the wall of a plenum chamber or air duct of a hot air furnace;

FIGURE 2 is a View taken along the line 2-2 of FIGURE 1;

FIGURE 3 is a top plan view of the water reservoir pan, overflow pan, and water nozzle of FIGURE l, other parts being omitted for clarity;

FIGURE 4 is an end elevation of the water nozzle used in this invention;

FIGURE 5 is a side elevation of the water nozzle illustrated in FIGURE 4;

FIGURE 6 is a view taken along the line 6 6 of FIG- URE 5;

FIGURES 7, 7A and 7B are front elevation, and elevation and bottom views respectively of the resilient valve seat memlber used 4in this invention;

rfice FIGURE 8 is a top plan View, of one end of the water reservoir pan used in this invention;

FIGURE 9 is a side elevation of the water reservoir pan illustrated in FIGURE 8;

FIGURE 10 is a view taken along the line lll-10 of FIGURE 8;

FIGURE 1l is a view taken along the line 11-11 of FIGURE 8;

FIGURE l2 is a `side elevation of the support bracket used in this invention;

FIGURE 13 is a view taken along the line 13-13 of FIGURE l2;

FIGURE 14 is a top plan view of the support bracket illustrated in FIGURES 12 and 13;

FIGURE 15 is an enlarged longitudinal vertical sectional view similar to FIGURE l but illustrating another embodiment of the invention;

FIGURE 16 is a fragmentary view in section showing a special finned tube for water inlet;

FIGURE 17 is a graph -comparing performance of the invention with other tilt-type humidifiers; and

FIGURE 18 is a fragmentary view showing a coiled tube.

Referring now more specifically to the drawings, there is illustrated in FIGURES l and 2 the humidifier assembly of this invention indicated generally at 10` mounted in an aperture 12 through the wall 14 of a plenum chamber or hot air duct of a hot air furnace `by means of an adaptor plate 16 rigidly attached to wall 14 by screws 18 extending through key slots 20. Through the combination of key slots and screws illustrated, adaptor plate 16 can be readily mounted on the wall 14 by positioning the round portion of key slots 20 over the heads of screws 18 and moving the plate downwardly until the narrow portions of the key slots are behind the screw heads, whereupon the screws are tightened to rigidly clamp adaptor plate 16 to wall 14. For removal of the assembly, the foregoing mounting procedure is simply reversed.

Adaptor plate 15 has a cut-out section indicated generally at 22 which is of substantially U-shaped configuration, the portion of the adaptor plate remaining adjacent the inside of cut-out section 22 forming a downwardly extending shield 23. A generally rectangular water reservoir pan 24, preferably of heat resistant glass or other non-corrosive material, tits through cut-out section 22 and has one end thereof detachably mounted on a tiltable support bracket to be described hereinafter. The shield Z3 is thus disposed transversely across the inside of water reservoir pan 24 and extends downwardly to a position closely adjacent the normal water level in the pan. An overflow pan 26 fitting in the bottom of cut-out section 22 and extending for a major portion of its length into the plenum chamber or air duct is rigidly secured to adaptor plate 16 by welds or other suitable means. Formed in the bottom of overllow pan 26 are elongated mounting grooves 28 (for mounting the support bracket) disposed in generally parallel relation to adaptor plate 16 and leading to a sump 3l) having a drain opening 32 in which there is inserted an overflow grommet 34 adapted to receive a length of tubing (not shown) for conducting overliow water to a suitable location for each installation.

A substantially vertical support bracket indicated generally at 36 and having legs 38 supported in the grooves 28 is pivotally or tiltaibly mounted in the bottom of overtlow pan 26. The support bracket 36 has outwardly extending spaced side arms 40 and bottom arm 42 disposed below and between the side arms 40, the arms being adapted to receive and support the sides and bottom respectively of reservoir pan 24 as shown in FIGURES 1 and 2.

A generally U-shaped spring clip indicate-d at 44 and f Y `havinglegsi6/and Lllias itslegidsecuredto th pip i n y ,supply civ/ate y ditionisniaintaine water@` aswbeen evaporatedtrom reservoir ten oued balance spring "75j totiltsupport f reservar/s211124amivalrelseatne mf'ffb SZtowardthefgreatly:exaggerated.positionasshown by fthe `pl1aritom*lines ,liin ,FGURE 1yr/thereby moving of reservoir 'pan k2st can.-`besecurely clampedfbetween support bracket 36 andleg 456, when screw` 59" isf tig ened as shownrin FIGURES l andfg y A valve seat member indicated generally f f rubber or like resilient material is slidabiyimounted `on" value seat member 52 `has a center planar section '56, Wsothat wateris discharged-intothepanfl untilthe'added opposite sides of whichforrn valve seating surfaces,y AEir- 1Qh weight at the predetermined water leveltiltsva'ive seating f tending outwardly on opposite sidesfronithe planar ineinberSZ baclcagainstuozzle 64 to shiitoithesupply section forming theivalve seating surfaces'areV generally otfwater. .-In general, the water levelfiiiy water reservoir 5 inverted `U-shaped hoods S8 having grooves 60 on the v pari zi-fwillvaryfbetween% andi inchfronithebottom! f under side thereofxadjacent the centerplanar section S6 thereof, thernini'rnuin beingl/z inch andthe maximum lV Y.

'whichr are adapted to slidally receive*tongue54.fS/Vith tongue 54- in either or thefgrooves 6u, tlie'ioppositeiside,VY of the'ceriter planar section 56 forms a vaiveiseating surinch for,fsatisfiict'ofry operation-z t. ,Abilityltofmaintairi ane'arly constant levelfoi`-waterfin y Athefreservoir underfthe widerange of `iii/ratersupply pres? L' face, thus makingthe valvese'at rnember52'reversible l In sure's encounteredinfthe field hasbeenafproblem ofgr'eat f" i' addition, contact friction between tongue/54 `andthe mlman *aumfanfculefs `0f hlmidel'fs tlll'd 0H? v ber valvefmember allows `the `valve, seat to bepositioned 2 Wlh heflQfef T105 bCeLSGlVCCl" 0H the Sofealledi,` -f vertically, thus providing `several fresh valvemsurfa'ces to "-til"tyl9il 01"! Cmmlerbalanced hufflide .h-Order* l@ y bee'xposed on each ysidebyy simple adjustment from 'time j Understand Whthiisbeen accomplished `byliiy inventiamo; to time. A desired space between legs 46 andliflis* lslllessafymgxpllnthe'loblemvfmd glye C,Ol'lfllfliff,r maintained by a screw 62 threadedthroughupper portion f SUV@ dabiled Undfideilllalet Cldllms` 011 van* of bracket 36 and leg 46 to abut against tonguei, ad... 25 CUS Wufkf-)Wntmiellllv lllklllSrf i, y, justinent of which will be described in inorefdetail heref .R 1S Weuknown lhat Water supply pssuresuvary ,Widely inafn iii diierentparts of the country. Normal Lwater pressure They weight of water reservoir pan 2,4 and itscontents t @Home Communitymaylbe. 30 Wands Per Squaw," mhr causes supportbracket 36y to-tilt in .a direction to move ',Norlmaipressu mi @umher ma may b5 loorpmids Per A the seating surface of valve seat member 52 `against,the 30V Sfillflll/ fi/12.311.153@ Weu'known hOWeVel" 17s' howl* discharge end of a horizontallydisposed nozzle 64 'attnef- 'l/ldy hseeua@jnofmalwlfffmurs may ,Vari/"fiom end of a constant source water ysupply pipe 66. i Thefnoz t? 1993 1011 a 139531?. "humldfer, inning-i103?, ,f zle 64 is swagedto a. conical shape `and partiallyciosed im?,SmmSystemsimdmamy affyme wipunds preSSure,'

y'adaptor tplate'lg toliousetbat portion' ofthe humidifier.

f from .the nozzle o@ when waterfninkreservoirfpai'ti `2li',

to provide a desired yreductionin sizetot.heavyWalled; f l??glssmfdgpttowypmiildsi'@ y pipe sr. Avnve (not Shown) `may be amnistia tra@ .entamer @esaminare sich; asrmmrfbwrepipe 66 to limit the maximum velocity'frorn nozzle' odas y Weihe cfimmllfiilyftqSuddilyun Pto '3l/@V100 pounds* desired. A portion or'thepipe 65 hasatriangularcross-i i .www Pressung .usfhm ;amaiitr'oullle when than sectional conguiiation as indicated at 68 so thatpipe 6 pl-.Qbalile tmporaryffau m humldanim ,Hmj'fiveff t may be rigidly and tatly clamped againstladapto ate egssyweprlefssu byqndmlmmdle law/@gan Y yJie-ayv a. britte in serments adapter eine intime/few media@ EWQW'W Pfbtflie f '72. Bracket 7u has' a flange portion Wildisposed sub-I i f A, Y i asl .Water Dyer the new' flaferfn. Stantially at right. angles to adaptor plated@ 4to support femfmsf i9 remedy 'a 'mndit'lonwhich 'no honger exlslsvme a removable cover 76 the sides of'whicliiit ilusliavairis'f umnfmd' @omet @wmf lmaytinker Wim thumt and i f f f :proba-blyputjitentirely outeotadiustniennor,iiiexasperam flmgultffjthefvvgater'snpplyfConditions werefencounw :tere i falls below a predetermined level. Ten'sionlori springf may be,v adyusted as fdesired by turning n ut Sti t0 com' r," communities pressure'at an elevatedspot near the reserpensate for the weight of water reservoir pan L24 and d0 y f j t l voirniay be 30 pounds. Each 1GO feet of elevation nroits contents, thereby maintaining valveseating member 5 y duces a 43 pound diierence in pressure. Thus a few 2 in a substantially balanced position against nozzle 64. blocks awa 'n th u th h lfqb I It also may be desirable to adjust the tension of s rin 78 'A y 1 e Va ey e pressure'ls muc' nu "el" t* in accordam with th ghr is not uncommon-'to find a 200 foot head difference be-` e e Wedel PleSSufeflt DOZZA? 6 I, a high tween houses in a valley and adjacent hill. PISSUF@ resulting m 1G55 @M1011 belflg required by the 6G All of the above emphasizes the importance of produc- SPIUging a humidifier Witha single valve and simple adjustment Sulfble Humber (twonbflplg SHOW?) 0f generally for universal installation and assured reliable operation T-Shapd eYaPOa'fOf pla's 05 OI any suitable eVauOraOr regardless of the special pressure conditions met in any platematerial have a base leg 38 slidingly fitting 1n `S Ub u specificy installation. How completely the present inven- `Stdltlauy Yel'lCal Channels 9*@ provided on the inner s1des 5D tion accomplishes this will be seen on the attached graph or reservoir pan 24 Legs 8 8 of the evaporator plates FIGURE I7.' `Anyinoreasefin Water pressure necessitates dip into the water in reservoir pan 2 4 and act as Wicks f a counteract-ingaforce sucient to close the water valve to transmit Water over the surfaces of the plates r8i', t

tightly to prevent overilow of the Areservoir or pan. lf the whereby the evporating rate of water from reservoirpan v design is such that overilowonce starts it will continue iny 24 can `bervaried in accordance Withtlie demandsfof the 70`definitely andrdamageyvill result unless the Overilow is* heating system by varying the number 'of evaporator` r connected. toga drainf W infreq n over the maximum pressure range with a minimum rise in the water level `in the pan.

FIGURE 17 expresses comparative results in graph form.

The present invention incorporates a novel combination of elementsto provide .maximum direct valving action with a minimum increase in weight of water in the pan. Of prime importance toward this end is the location of the support pivot or fulcrum 28 of the pan at the end of the water collecting area so that every drop of water entering the pan will add its weight as a force to directly urge the valve toward closed position.

A commercially available humidifier of the same general type having a support fulcrum near the longitudinal middle of the pan was tested under Iworking conditions and produced the results shown in curve A of FIGURE 17. After being set to close at 30 pounds pressure with one inch of water in the pan, the depth of water rose to 3 inches (which is the depth of Itheir pan) and overflowed at 90 pounds pressure.

Another known type of humidifier on the market operates yby lwater weight against a rubber diaphragm and curve B of FIGURE 17 setting forth results of a test under working conditions shows that with a water depth of 1/2 inch at 30 pounds pressure, the Water level had increased to 11/2 inches (in la 2% inch pan) at 130 pounds pressure.

A third commercial humidier was tested which operated lthru a combination of levers leading to an outside valve. With 1X2 inch Water at 30 pounds the water level rose to 1% inches (in a 2 inch pan) at 130 pounds pressure as shown in curve C of `FIGURE 17.

The foregoing are representative of the humidifier art in commerce today.

The humidifier of the present invention, operating thru a simple counterbalance, with 1/2 inch water at 30 pounds increased to a total of 2%; inch (in a 21A; inch pan) at 13() pounds pressure as shown in curve D of FIGURE 17.

When valve lseating member 52 is in a position to open nozzle 64, hood 53 over the acting valve seat surface deflects water being discharged from the nozzle 64 downward-ly into the reservoir pan 24. Thus positive filling of reservoir pan 24 is assured because all water from the nozzle 64 is deflected into the reservoir pan 24 with none escaping in the form of a spray to fall outside. Another feature of the valve seating member 52 is that it is slidable up and down on the tongue 54 of spring clip 44. As the valve seating surface which abuts the end of nozzle 64 becomes Worn, the valve seating member 52 may be moved upward slightly so that a new seating surface will abut the end of nozzle 64. When all available surface area on one side of the central planar section 56 has been Worn, the valve seat member 52 may be removed and reversed so that tongue 54 is inserted in the groove 6) adjacent the worn seating surface. Thus valve member 52 has a much longer usable life span than those valve members having only one seating surface area. Thus valve member S2 in the combination described is novel in that it combines several advantages: (l) lt is a single molded member providing a multiplicity of new valve surfaces. (2) It is readily removable for visual inspection and slips on and off readily without necessity of screws or other means of attachment. (3) The recessed flange on each side serves alternately as retainer and water deflector into the reservoir.

rPhe adjustment screw 62 permits positioning of valve seating member 52 in relation to the adjusted position of reservoir pan 24, thereby making it possible to obtain a substantially parallel valve seating surface in relation to the discharge end surface of nozzle 64.

Another feature of the humi-dier of this invention is that overflow pan 26 acts as a shield to prevent upwardly moving air currents in the plenum chamber or duct from impinging ydirectly on the bottom of reservoir pan 201 which would tend to upset the balance of the members associated with ti'ltable support bracket 36 and cause water to be discharged into the reservoir pan 24 when none is needed. The overflow plan 26 also acts as a safety feature if for any reason the reservoir pan 24 should be overlled. Thus itis not possible for water to accidentally enter the plenum chamber or air duct in which the humidifier is mounted.

Leakage of hot air through adaptor plate 16 is -held to a minimum because shield 23 extends adjacent the normal water level inside reservoir pan 24. Thus shield 23 in icombination with cover '76 effectively prevents leakage of hot air from the system.

Referring now to FlGURE 15, there is illustrated another embodiment ofthe humidifier of this invention which operates in exactly the same manner as described hereinabove. The construction is substantially the same as illustrated'in FIGURE l except for the water supply nozzle, its mounting, and the removable cover. In this embodiment an adaptor plate indicated generally at 10) is rigidly attached to a plenum wall 192 in the same manner as illustrated in FlGURE l. The adaptor plate 11141 has a square recess 11i-6 in which there is a hole 10S through the bottom thereof for mounting a nozzle retainer member indicated generally at 111i.

The nozzle retainer `member 111i has a square body in which there is a right angle iiow passageway 112 therethrough having a jet discharge nozzle 114 threaded in one end thereof and extending axially from the retainer member body and a water supply pipe 116 suitably connected to the other end of the passageway and extending radially of the retainer member body. A threaded stud 118 integral with nozzle retainer member 110 extends therefrom in axial alignment with discharge jet nozzle 114 and is received in the hole 108. A nut 121i threaded on the -stud 118 rigid-ly clamps retainer member 111i to the supporting shield 164, the square recess 1116 permitting the pipe 116 to lie substantially flush against the adaptor plate ltlil'. The angle at which water supply pipe 116 extends from the humidifier assembly can be pivotally adjusted to any of three radial positions (namely, vertical or horizontally to left or right) about the longitudinal axis of retainer member 11d by loosening the nut 120 on stud 118, thus simplifying installation of water supply pipe connections. A flexible heat insulating cap 121 may be slipped over nut 12) to reduce heat flow into the valve.

An upper edge of a removable cover indicated generally at 128 has spaced upright tabs 124 formed thereon which are adapted to extend through correspondingly spaced horizontal slots 126 in shield 104 land abut against the back surface thereof to hold the cover in position. An opening 127 is provided through the top of cover 122 'between the tabs 124 to accommodate the Water supply pipe 116. It should be understood of course that the position of opening 127 will depend upon whether pipe 116 enters through the left or right side of cover 122, or through the top as illustrated. The lower end of `cover 128 is secured to the adjacent end of an overflow pan 129 by a screw 130 threaded into a screw clip 132 clamped over the side of the overflow plan. ln practice, cover 122, may have three semi-circular tabs (not shown) all cut, 'but not removed at the three locations where the tube 116 may make its exit. At the time of installation, one such tab is knocked out to correspond to the preferred position of tube 116 on that particular installation.

Lime and related material in solution in the water supply to humidifiers is eventually deposited as solid matter upon evaporation of the water in the unit. The greater i i i? i i entlbys g 47MWith ejatirfowk t ',chamb'ar; they interyening Wnlis" te hen qwiiileiie" airtig t Valve from the 'supply line issn f peses bnt'ge'xperienee prqlesoth' is lovvgaetually `mi ching 'the eyagp "rati ,:ifier,`` and this usually, y'citiesnot exceed waterinthe,valvetreaehingusuxrnndinfftemperatur l jieiegsingx its beffite'.k the "filent j means must besxtppliedto `effectively cool thejyaiife and' ik One essential factor in this accomplishment sto-keep Kv the valve 4anni tubey area insidetheweoveniand so jexposedf be used in 'extreme cases to furtherfieducefheatfombut stlchuse is optimiaLkr w upportfb cketorblasingsaid balance 1 sp Cifk Sa, l

i Till@ length of oppertubingise arianne; inside k t n covers 76 andy E28 is 'short but the length of tubing, in t y i theieutside ycool air n'iuehy longerl tougmenLthe heat i n u k l ,di'sspat-ing, capacity. sjths entire' tlib'e" `is "suppiid' i "rkhjwtm ,e fior H2131@ HQVQSE llml El anintegral part f the faetforyassembw itannotfbe left. t ttlltllly;'hoi-izo'ntaivzniis;` said snppnrt brzieketjhm/ing` i, 'off during field installatiem; Copper `being an excellent Mowerfcnwardlyxtendig arm; andfspacedupperwrheat conductor, the noutward heat oW is ratp/yid,y Thisgis IQS'PODADEQUWYW @Xelldlg arms adp'fed t ,SU'PECYk further augmented bynsing tubing of, at least doubleusualA "s a Abottonmet sides iespectively of Aalwateij reservoir` 192111,); i wall thiekness asfshown inFIGURES'Svandf @V63 and 170 ahreservoirpnfsuizprtedw' YSaid Macken, asprneclip; 'in rFIGURE 15 at 116A--Amp1e heatiqwkeapaeityfis l basvingia,pairfospacedlegsjoiningeaehdnthelffat Voneend.; I, f assured. ff f; Y' 3- f TonefSidllegsbeingseeiire-dadjaeenfanmendwoposite K'Ifiiisfmnstinowibe followed by ampleheatvdissipat y n 'ffrmitsfnjeinedend'to said snpportibreeketfi, i

capacity. Asfftube `116 is iongfand `heavy it'eannot 'bei amp aideof saidreser .k3y @The assembly @file aim lvwherein, means are? Pm. n fv'iciedl for* adiustingxlhef tension offfsaid balanceifspnn A ei ompri'sing:iasubstantiaily verticalsnp adaptedtidetachgbly 1 fffbent duringfaetqry assemblyorinfpgekingithe xnit,` with '1175 rtosaiyz "UpPQrt braak jacent the end of the other of said legs, a water nozzle having a discharge end opposite said valve seat for supplying water to said reservoir pan, the weight of said reservoir and its contents tilting said supportbracket toward said nozzle to move said valve seat to a position to close the discharge end of said nozzle when water in said reservoir pan is at a predetermined level, a balance spring operably connected to said support bracket biasing the supportbracket and valve seat in a direction away from said water nozzle when water in said reservoir pan is below said predetermined level to open the discharge end of the nozzle to reiill said reservoir pan to said predtermined level at which point the weight of the reservoir pan and its contents tilts said support bracket to a position to close the discharge end of said nozzle.

5. The humidier of claim 4 in which a screw is threaded through a leg of said spring clip to abut against the opposite leg to provide for adjustment of the width of space between the two legs.

6. A humidiiier comprising a water reservoir pan, means mounting said reservoir pan for tiltable movement about a substantially horizontal axis in response to a predetermined water level in said pan, a water nozzle positioned above said reservoir pan, a valve member mounted on the means mounting said reservoir pan and adapted to open and close the discharge end of said nozzle in response to the tiltable movement'of said reservoir pan, said valve member comprising a valve seat disposed substantially vertically when in an operative position, and means for vertically adjusting said valve member to position different valve seat areas thereof for engagement with the discharge end of said nozzle.

7. A humidifier comprising a water reservoir pan, means mounting said reservoir pan for tiltable movement about a substantially horizontal axis in response to a predetermined water level in said pan, a substantially horizontally disposed water nozzle positioned above said reservoir pan, a reversible valve member adapted to open and close the discharge end of said nozzle, said reversible valve member comprising a planar section forming a valve seating surface on opposite sides thereof, said seating surfaces being disposed in a substantially vertical plane when in anI operative position, -a pair of hoods extending outwardly from the top and sides of said planar section in opposite directions, a groove in the underside of each of the hoods adjacent said planar section, means including a tongue carried by said reservoir and slidably fitting in one of said grooves for mounting said valve member with one side of said planar section against said nozzle when the water level in said reservoir is at a predetermined level.

8. A humidifier assembly for mounting in a wall aperture of a plenum chamber or duct of a hot air furnace, an adaptor plate adapted to be secured to the Wall of said plenum chamber or duct, an aperture in said daptor plate opposite said wall aperture when the adaptor plate is mounted on the wall of said plenum chamber or duct, a substantially horizontally disposed overflow pan rigid with said adaptor plate and extending through the aperture therein, means in said overflow pan mounting a tiltable substantially vertically disposed support bracket, means for detachably securing a water reservoir pan on one side of said support bracket and over said overflow pan, a shield on said adaptor plate extending transversely across the inside of said water reservoir pan and downwardly to a position closely adjacent the bottom of the reservoir pan, a tensioned balance spring operably connected to a side of said support bracket opposite from the side on which said reservoir pan is secured for biasing said support bracketin a direction opposite from that in which it is urged by the weight of said reservoir pan and its contents, a substantially horizontally disposed water nozzle mounted on said adaptor plate over said reservoir pan and directed toward said support bracket, means mounting a valve seat on said support bracket adjacent an upper end thereof and opposite from said nozzle, said valve seat being adapted to close said nozzle when water in the pan is iilled to a predetermined level.

9. A humidifier assembly comprising a counter-balanced tiltably mounted receptacle, a nozzle having a discharge end for supplying water to said receptacle, valve seat means adapted to abut and close the discharge end of said nozzle in response to a predetermined water level in said receptacle, a stationary nozzle retainer member having a flow passageway therethrough connecting with said nozzle, means mounting the nozzle on said retainer member, a water supply pipe connected to the flow passageway of said retainer member, a threaded mounting stud on said retainer member extending therefrom at substantially right angles to said water supply pipe, support means having a hole therethrough for receiving said stud, and a nut threaded on said stud rigidly clamping said retainer member to said support means, said stud permitting pivotal adjustment of said water supply pipe about the axis of said retainer member.

l0. A counterbalanced humidiier assembly comprising an evaporator receptacle tiltably mounted at one end on a substantially horizontal axis and having an open top, said axis being located below said receptacle, a relatively stationary discharge conduit having an open end located above said top near said one end providing a substantially horizontal discharge opening, a valve member secured to said receptacle at said one end and adapted to engage said discharge opening, and means including balancing spring means biasing said receptacle to tilt in a direction to move said valve member away from said opening, the weight of said receptacle and contents serving to tilt said receptacle to forcibly directly engage said valve member with said conduit end to close said discharge opening when a desired liquid level is attained in the receptacle and to permit said spring means to oppositely tilt the receptacle when said level falls.

l1. A counterbalanced humidifier assembly comprising a support mounted for tilting about a substantially horizontal axis, an open-top evaporator receptacle removably mounted adjacent one end upon said support above the pivot axis and extending generally horizontally away from said pivot axis, a relatively stationary liquid discharge conduit extending to dispose its open end adjacent the open top of said receptacle, spring means connected to the support for balancing the weight of said receptacle and its contents, means for adjusting said spring means for deter-mining the maximum liquid level in said receptacle, a valve member carried by said support adapted to forcibly engage directly and close said open end of the conduit Whenever said receptacle contains a predetermined amount or more of liquid to be evaporated, said spring means tilting the support to uncover said open end of the conduit to permit liquid flow into the receptacle whenever the liquid in the receptacle falls below a desired level, and means for adjusting said valve member toward and away from said one end of the discharge conduit.

l2. In the humidifier defined in claim 6, a hood extending outwardly from the top and sides of said valve seat, the hood being disposed over the discharge end of the nozzle in a manner to deflect water discharged therefrom downwardly into said reservoir pan when the valve member opens the water nozzle.

13. In a counterbalanced humidifier assembly, an open top evaporator receptacle mounted at one end to tilt about a generally horizontal axis, a relatively stationary liquid discharge nozzle disposed to supply fluid to said receptacle adjacent said one end, a valve member for engaging said nozzle, a substantially U-shaped spring mount having one leg secured to the receptacle and the other leg mounting said valve member adjacent the nozzle, and balancing spring means biasing said receptacle to tilt in a direction to move said valve member to uncover said discharge nozzle, said receptacle tilting in the opposite 

